Americans have always liked “elimination” diets, in which a certain food or nutrient is banned, either for health reasons or weight reasons. For the 1% of the population who suffer from celiac disease, in which the body has an immune reaction to gluten, with digestive and nutrient-absorption consequences, going gluten-free is essential. But today, more than 30% of Americans want to avoid gluten, which explains why the market for gluten-free foods is now more than $10.5 billion a year. Part of this is driven by the critique of refined carbs in the diet and their possible link to obesity and heart disease.

Going gluten-free can improve your diet if it means cutting out a lot of empty-calorie carbs (like those from sugar), refined-flour-based snacks, and even foods like salty hot dogs and bottled sauces, where gluten is used as an emulsifier. If you focus on more whole foods—vegetables, fruits, grains—all the better. Even if you’re not going gluten-free, the popularity of gluten-free whole grains like quinoa has enriched supermarket shelves and restaurant offerings.

All that said, gluten-free does not automatically equate with “healthy.” Some gluten-free foods are higher in calories or fat than the wheat-based products they replace. And, of course, it’s always possible to make gluten-free junk food.

WHAT IT IS Gluten is a strong, stretchy protein that forms when wheat flour and water mix. It helps make pasta al dente, pastries crisp, and artisanal breads crusty and chewy.